Pump



July 5, 1966 w. G. MOKENZIE PUMP Filed NOV. 2, 1964 United States Patent() 3,259,070 PUMP William G. McKenzie, Racine, Wis., assgnor to Walker Manufacturing Company, a corporation of Delaware Filed Nov. 2, 1964, Ser. No. 408,069 15 Claims. (Cl. 10S- 43) v This' invention relates generally to fluid pumping means, and more particularly, to' an apparatus for providing a sudden rise in pressure in a iiuid metering system.

In general, the pumping device of the present invention is characterized by an extremely simple and cornpact unit which includes a thermal-actuated piston assembly and a .positive displacement fluid accumulator chamber. Suitable valve means is also provided wherein upon .actuation of the aforesaid piston assembly, the uid pressure within the accumulator chamber will increase a predetermined amount, at which time the valve means will rapidly open to permit the fluid under pressure within the accumulator chamber to surge into an associated fluid metering system.

It is .a general object of the present invention to provide a iluid pumping device of the above character that is simple in construction and operation and which is thus economical to commercially produce.

It is another object of the present invention to provide a fluid pumping device of the above character which has very few moving -components and therefore has a long service life.

It is still another object of the present invention to provide a iluid pumping device of the above character that may be energized by electricity provided by universally available house current.

Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a longitudinal cross sectional view of a preferred embodiment of the pumping device of the present invention;

FIGURE 2 is a transverse cross sectional View taken along the line 2-2 of FIGURE l; and

FIGURE 3 is a top elevational view, partially broken away,l of the pumping device illustrated in FIGURE l.

Referring now to FIGURE 1 of the drawings, a fluid pumping device 10, in accordance with the preferred embodiment of the present invention, is shown operatively secured to a generally L-shaped mounting bracket 12 having a horizontally extending lower section 14 and an upwardly or vertically extending section 16. Rigidly secured to the right end of the mounting bra-ckets lower section 14, as 'by a suitable machine screw 18, is a piston housing 20 that is formed with a central annular bore which deines a fluid accumulator chamber, generally designated 22. Reciprocally mounted within the chamber 22 is a hollow, elongated, cylindrical piston member 24 having .an end portion 25 which closes the right end thereof. A suitable O-ring sealing member 26 is compressed between an annular recess 27 formed around the inner periphery of the chamber 22, and the outer periphery of the piston 24, which member 26 serves to prevent any iluid leakage between the left end of the chamber 22 and IC@ l the piston 24. Threadably mounted within the end of the piston 24 opposite the end portion 25 thereof is a medial section 28 of an annular spring retainer member 30. The retainer 30 includes a peripheral cup section 32 which extends radially outwardly from the periphery of the piston 24 and functions to support the left end of a helical return spring 34 that extends coaxially around the piston 24 and is maintained under a state of slight compression between the cup section 32 of the retainer 30 and a radially outwardly extending shoulder section 36 formed around the left end of the piston housing 20.

The right end of the iluid accumulator chamber 22 is closed 'by a radially inwardly extending section 38 of the housing 20, which section 38 defines a central ybore 40 that is located coaxially of the chamber 22. A cylindrical cup-shaped piston housing cover member 42 is threadably secured within `and closes the right end of the housing 20. The end section 38 of the housing 20 is formed with a raised annular valve seat portion 44 circumjacent the bore 40, against which is seated a resilient and deformable diaphragm 46 that is preferably fabricated of a fluid impervious rubber or the like and which is secured to the right end of the housing 20 by having its outer periphery compressed between the end of housing 20 and an annular shoulder section 48 formed around the interior of the cover member 42. It may be noted that the outer periphery of the diaphragm 46, by virtue of being thus compressed between the end of the housing 20 and the cover member 42, acts as a gasket or sealing means to prevent any uid from leaking from the right end of the housing 20. The diaphragm 46 is resiliently urged into engagement with the valve seat portion 44 formed around the bore 40 by means of a substantially ilat disk-shaped spring retainer cup 50 which is resiliently engaged with the right side of the diaphragm 46 by a coil spring 52 that is nested within the interior of the cover member 42.

As best seen in FIGURE 3, a radially inwardly extending fluid passage 54 is formed in one side of the housing 20. Threadably mounted within the outer end of the passage 54 is a suitable fluid fitting 56 which is adapted to communicate fluid from an associated uid inlet conduit 58 to the passage 54, from where this fluid is transmitted into the interior of the accumulator chamber 22. A suitable one-way check valve is provided within the interior of the tting 56 by means of a spherical valve member 60 which is resiliently seated against a suitable O-ring sealing member 62 by a helical coil spring 64. Fluid is communicated out of the accumulator chamber 22 through a fluid outlet passage that is provided by an annular recess 66 which is formed in the outer (right) side of the end section 38 of the housing 20, which recess 66 is communicable through a bore 68 formed in the side of the member 20 with an outlet iitting 70 that is threadably secured Within the outer end of the bore 68, as seen in FIGURE 1. The fitting 70 is secured to a suitable fluid outlet conduit 72 which is adapted to transmit fluid pumped by the device 10 to an associated iluid metering or dispensing mechanism, as will be described.

Actuation of the pumping device 10 of the present invention is achieved through the use of a thermal energized motor, generally designated 74, that is disposed within an elongated cylindrical housing 75 which extends coaxially through an annular opening 76 formed in the upwardly extending section 16 of the mounting bracket 12. The housing 75 also extends through a central opening 78 formed in a flat disk-shaped retainer 80 which is resiliently urged into engagement with a radially outwardly extending shoulder section 82 formed on the right end of the housing 75 :by a helical safety spring 84 which is compressed between the upwardly extending section 16 of the bracket 12 and an annular recess 86 formed in the left side of the retainer 80 circumjacent the opening 78. As seen in FIGURE 3, a pair of generally L-shaped retainer clips 90 and 92 are secured at their right ends to the opposite sidesV of the retainer 80 lby suitable screws 94 and 96, respectively, which clips 90 and 92 have their opposite (left) ends bent inwardly or toward one another and engaged with the outer or left side of the upwardly extending section 16 of the mounting bracket 12, whereby the retainer 80 and motor housing 75 `are free to move toward the 'bracket section 16 but are prevented from moving more than a predetermined distance away from the section 16 by the brackets 90 and 92.

The thermal motor 74 is preferably of the wax pellet type and includes a suitable electric heating element (not shown) which is adapted to be energized by connecting a suitable source of electric current, such as house cur-- rent, with a pair of lead lines 97 which are communicable with the heating element. Upon energization of the heating element, a wax pellet that is located within the housing 75 adjacent the heating element expands a predetermined amount thereby biasing a piston rod 98, which extends coaxially through a central bore 100 formed in the medial section 28 of the retainer 30 and also through a central opening 102 in the end portion 25 of the piston member 24, outwardly to effect actuation of the pumping device 10. As illustrated in FIGURE 1, suitable sealing means in the form of a conventional O-ring 104 is provided between the inner periphery of the opening 102 and the outer periphery of the piston rod 98 to prevent any fluid flow between the accumulator chamber 22 and the interior of the piston 24.

The left end of the piston rod 98 is formed with an enlarged diameter section 106 against which an annular spring retainer 108 that is slidably mounted on the rod 98 is resiliently biased by a coil spring 110 that extends coaxially within the interior of the piston 24. A retaining ring 107 is provided on the outer or right end of the piston lrod 98. The ring 107 is located on the end of the rod 98 such that when the hod 98 moves toward the right, the outer (right) end thereof engages and unseats the diaphragm 46 from the valve seat portion 44. rI'he reason for this is that in the event air becomes trapped within the fluid accumulator chamber 22, the pessure increase within the chamber 22, upon operation of the device 10, Will not be sufllcient to effect unseating of the diaphragm 46.

Secured to the top of the spring retainer 80, as by Welding or the like, is an L-shaped actuating switch support bracket 112, to which an actuating switch 114 is rigidly attached by suitable bolts 116 and nuts 118. The switch 114, which is of a conventional toggle-type and connected With the aforementioned source of electric current used to energize the thermal motor 74, i-s adapted to be actuated upon engagement by -a suitable tripping means which is provided herein by a bolt 120 and nut 122 that are adjustably secured to the upper end of a Z-shaped bracket 124 rigidly secured, as by welding, to the upper end of the mounting bracket section 16. The side of the actuating switch 114 opposite that which is engageable with the tripping means provided by the bolt 120 is engageable with another bolt 126 which is threaded within the upper end of a bracket 128 and secured by a locknut 130, the bracket 128 being secured at its lower end to the top of the spring retainer 30. Engagement of the bolt 126 with the switch 114 serves to reset the actuating mechanism within the switch 114 that is tripped upon engagement of the switch 114 with the bolt 120, as will hereinafter be described.

Assuming that the lead lines 97 are connected to a suitable source of electric current, and that the fluid inlet and outlet conduits 58 and 72 are connected to an appropriate source of fluid and to an associated fluid metering or dispensing device, respectively, the operation cycle of the pumping device 10 commences upon energization of the thermal motor 74, as by actuating an external switching mechanism (not shown) to complete the electrical circuit to the motor '74. Upon energization of the motor 74, the piston rod 98 will be biased outwardly or away from the right end of the motor housing 75, thereby compressing the coil spring 110 between the spring retainer 108 and the end portion 25 of the piston 24. As the lspring 110 becomes compressed within the interior of the piston 24, the piston 24 is resiliently urged toward the right end of the fluid accumulator chamber 22, whereby the annular spring retainer 30 that is threadably secured to the left end of the piston 24 compresses the helical return spring 34 between the cup section 32 of the retainer 30 and the radially outwardly extending shoulder section 36 formed around the left end of the housing 20. As the piston 24 moves toward the right end of the accumulator chamber 22, the fluid pressure within the chamber 22 will begin to increase, the reason for this being that the spherical valve member 60 prevents fluid within the chamber 22 from being forced back into the fluid inlet conduit 58 and the diaphragm 46 prevents fluid within the chamber 22 from passing into the outlet passage provided by the annular recess 66 and the bore 68. It will be noted that the spring 110 is preloaded such that the piston 24 must create a pressure of approximately 60 p.s.i. within the accumulator chamber 22 before the spring 34 will further compress, and that when the spring 110 is fully compressed, the fluid pressure within the chamber 22 is approximately 90 p.s.i. The spring 52 is preferably constructed such that the retaining cup 50 maintains the diaphragm 46 engaged with the valve seat portion 44 until such time as the fluid pressure within the accumulator chamber 22 is approximately 10() p.s.i. When the spring 110 is fully compressed, the fluid pressure within the chamber 22 will ri-se above 100 p.s.i. due to the continued forward movement of the piston rod 98, thereby causing the diaphragm 46 to relieve the pressure within the `chamber 22. Due to the force exerted on the piston 24 by the compressed spring 110, when the pressure is relieved within the chamber 22, the piston 24 will rapidly move toward the right, forcing or causing the fluid to surge out of the chamber 22 and through the fluid outlet passage provided by the annular recess 66 and bore 68, from where this fluid is communicated through the fluid outlet 72 to the associated fiuid metering or dispensing device. It will be noted that although a relatively high pressure (approximately 100 p.s.i.) is required to unseat the diaphragm 46 from the valve seat portion 44, only a relatively low pressure is required to maintain the diaphragm in an open or unseated position. This is due to the area differential between the entire area of the diaphragm 46 and the relatively small area thereof which registers with or confronts the bore 40, Accordingly, by properly selecting the area differential, as above described, together with the spring force of the spring 52, the diaphragm 46 may be designed to open or become unseated at virtually any pressure and thereafter close or become seated at any lower pressure.

The forward movement of the piston rod 98 is terminated when the retaining ring 107 engages the end section 38 of the housing 20; however, the thermal motor 74 continues to operate whereby both the motor 74 and motor housing 75 are biased toward the left or in the opposite direction from the aforediscussed forward movement of ythe piston rod 98. As the motor housing 75 moves toward the left, the spring retainer also moves toward the left against the resistance of the safety spring 84 until the actuating switch 114 engages and is tripped by the bolt 120 threaded in the `upper end of the bracket 124. When the switch 114 is thus actuated, the electric circuit communicating current to the thermal motor 74 is broken, at which time the heating element within the motor housing 75 is turned off permitting the wax pellet also located within the housing 75 to cool and subsequently contract.

When the motor 74 is deenergized, the return spring 34 which was compressed during the discharge portion of the operational cycle of the device forces the spring retainer 30 toward the left, whereby the bolt 126 mounted on the top of the retainer 30 is biased into engagement with the actuating switch 114 to reset the actuating mechanism therewithin, thus preparing the pumping device 10 for its next successive cycle, as hereinabove described.

It will be seen from the foregoing construction that the pumping device 10 of the present invention provides an extremely simple and compact unit which has very few moving parts and thus may be manufactured at an extremely low cost. The device 10 will nd particular application when used with an associated fluid metering device such as a device for metering successive charges of suitable lubricant fluids to a series of bearing surfaces in a production machine or the like. It will be apparent,

however, that the pumping device 10 of ythe present in;

vention is not limited to such use and may be incorporated in anyone of a number of well known lluid systems which use a fluid source under pulsed pressure.

While it will be apparent that the preferred embodi- -ment herein illustrated is well calculated to fullill the objects above stated, it will be appreciated that the pumping device 10 of the present invention is susceptible to modication, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. In a fluid pumping device, a housing delining a pumping chamber, piston means reciprocable within said chamber, valve means controlling the liuid liow to and from said chamber, actuating means for effecting movement of said piston means within said chamber, control means for effecting energization of said actuating means,

and means including spring means interconnecting said means on said mounting bracket for actuating said switch means when said switch means and said bracket are moved relative -to one another.

5. In a lluid pumping device, a housing defining a fluid pumping chamber, a piston reciprocable within said chamber, a motor for moving said piston in one direction within said chamber, switching means for effecting deenergization of said motor and being movable with said motor relative to said housing, tripping means for actuating said switching means rigidly mounted relative to said housing, said piston being engageable with a portion of said housing resulting in said switching means being moved into engagement and being actuated by said tripping means.

6. The invention as set forth in claim 5 wherein said motor is movable with said switching means relative to said housing and said tripping means.

7. In a lfluid pumping device, a pumping housing having a fluid accumulator chamber formed therein, a fluid pumping piston reciprocable within said chamber, an actuating motor movably mounted relative to said housing,

switchmeans for controlling energization of said motor, a piston rod extending Ithrough said piston and movable piston means with said actuating means whereby said piston is movable in one direction to force fluid from said chamber and said actuating means is movable in the opposite direction into engagement with said control means to effect deenergization of said actuating means.

2. In a fluid pumping device, a housing delining a fluid pumping chamber, a substantially hollow piston reciprocable within said chamber, power means for moving said piston in one direction within said chamber, a piston rod movable by said power means and extending through said piston, and spring means interconnecting said piston rod with said piston whereby said piston rod and said piston are movable relative to one another such that said piston is moved within said chamber to force fluid therefrom after said piston rod has moved a preselected distance within saidlpiston.

3. In a uid pumping device, a mounting bracket, a housing secured to one end of said bracket and defining a pumping chamber, a piston means reciprocable within said chamber, a piston rod movable relative to the piston means, valve means on said housing for controlling lluid flow to and from said chamber, power means movably secured to said bracket for moving said piston in one direction within said chamber, switch means movable relative to said bracket and said power means for effecting deenergization of said power means, and spring means disposed within said piston means resisting movement of said piston rod relative to said piston.

4. The invention as set forth in claim 3 which includes in one direction within said chamber upon actuation of said motor, and spring means interposed between said piston rod and said piston, said pist-on rod being movable relative to said piston and thereby compressing said spring means within said piston, said piston rod being engageable with a portion of said .housing whereby said switch means and said motor are biased into engagement with each other to effect deenergization of said motor.

8. The invention Ias set forth in claim 7 which includes ya return spring that is compressed upon forward movement of said piston and which biases said piston in a direction opposite of said forward movement upon deenergization of said motor.

9. In a fluid pumping device, a pumping housing having `a fluid accumulator chamber formed therein, a fluid pumping piston reciprocable within said chamber, a piston rod extending through said piston, spring means inter-` posed between said piston rod and said piston, valve means for selectively relieving the liuid pressure in said chamber, and means for; moving said piston rod relative to said piston whereby said spring means becomes compressed` until predetermined fluid pressure conditions are reached within said chamber at which time said valve means will open and said piston will rapidly move Within said chamber under the yinfluence of said compressed spring means.

10. The invention as set forth in claim 9 wherein said valve means comprises a differential area-type valve.

11. The invention as set forth in claim 9 wherein said piston rod is engageable with said valve means to selectively relieve the pressure within said chamber.

12. In a fluid pumping device, .a mounting structure, a housing rigidly` secured to said structure and defining an annular fluid accumulator chamber therewithin, one end of said housing being formed with an inwardly extending section defining a discharge opening, a valve seat formed around said opening, valve means resiliently engaged with said valve seat .and adapted to communicate said opening with a discharge passage formed in said housing when preselected liuid pressure exists within said chamber, a hollow cylindrical piston reciprocable within said chamber, a motor secured to said mounting structure, a piston rod movable upon energization of said motor, said pist-on rod extending through said piston and being movable :relative thereto, spring means within said 13. The invention as set forth in claim 12 wherein said motor is movably secured to said mounting structure and is engageable with said switch tripping means when said piston is moved a preselected distance within said accumulator chamber.

14. The invention as set forth in claim 12 wherein said motor comprises an expandable Wax pellet .and a heating element for effecting expansion of said pellet.

15. The invention as set forth in claim 12 wherein said valve means comprises .a resilient and deformable diaphragm which is resiliently urged against said Valve seat by a spring member supported adjacent said accumulator chamber.

References Cited by the Examiner UNITED STATES PATENTS Kocourek 103-53 Bradbury 103-53 Heitger 103-53 X Tice.

Larigne 103-53 Hamilton 230-55 X Dickey 103-53 ROBERT M. WALKER, Primary Examiner.

W. L. FREEH, Assistant Examiner. 

1. IN A FLUID PUMPING DEVICE, A HOUSING DEFINING A PUMPING CHAMBER, PISTON MEANS RECIPROCABLE WITHIN SAID CHAMBER, VALVE MEANS CONTROLLING THE FLUID FLOW TO AND FROM SAID CHAMBER, ACTUATING MEANS FOR EFFECTING MOVEMENT OF SAID PISTON MEANS WITHIN SAID CHAMBER, CONTROL MEANS FOR EFFECTING ENERGIZATION OF SAID ACTUATING MEANS, AND MEANS INCLUDING SPRING MEANS INTERCONNECTING SAID PISTON MEANS WITH SAID ACTUATING MEANS WHEREBY SAID PISTON IS MOVABLE IN ONE DIRECTION TO FORCE FLUID FROM SAID CHAMBER AND SAID ACTUATING MEANS IS MOVABLE IN THE OPPOSITE DIRECTION INTO ENGAGEMENT WITH SAID CONTROL MEANS TO EFFECT DEENERGIZATION OF SAID ACTUATING MEANS. 